ISSN:0038-9056    

DOI:10.1002/star.19750270203

出版商:WILEY‐VCH Verlag GmbH    

年代:1975

数据来源: WILEY

摘要:

AbstractLintnerized Starches. Chromatographic and Enzymatic Studies of Insoluble Residues from Acid Hydrolysis of Various Cereal Starches, Particularly Waxy Maize Starch.Native cereal starches, particularly waxy maize starch, have been carefully hydrolyzed at 35°C with hydrochloric acid (2,2‐N)in heterogeneous phase.Observation of the course of hydrolysis as a function of time makes it possible to classify the starches according to their acid lability. The kinetic values distinctly reveal two phases, i.e. a fast hydrolysis of the amorphous fraction and a slower degradation of the crystalline starch grain fraction. This observation was confirmed by X‐ray diffractometric patterns. The hydrolysis speed of acid resistant fractions seems to become slower as the apparent amylose ratio increases.The change in the macromolecular structure of the obtained granular residues or “lintnerized” starches as a function of time was examined after aqueous solubilization by means of gel chromatography using a calibrated Sephadex G‐50 column. Lintnerization causes a decrease in the apparent DP of the chains of the starch residues and two subgroups with apparent DP 13 and 25 appear rapidly. These DP are unchanging with time of acid treatment.The chromatographic and enzymatic studies of lintnerized starches were performed directly and after successive enzymatic digests with pullulanase and ß‐amylase. After debranching of solubilized residues with pullulanase and gel chromatography a linear chain subgroup of DP 15–20 appears. This one is in fact composed of two subgroups: one more important with a DP 13, the other broad distribution with a DP 15–25. The comparison with the subgroups observed before debranching shows that a main part of the initial subgroup of DP 25 could be considered as formed with singly branched chains. Furthermore a small proportion of pullulanase resistant ß‐limit dextrins was obtained.The obtained results permits one to suggest a new model for the structure of waxy maize amylopectin. On the basis of this model the differences in structure existing between the various starches are discussed and the results are compared with those reported elsewhere for potato starch. A parallelism between crystalline patterns of native starches and the amylopectin structure, particularly its branching

ISSN:0038-9056    

DOI:10.1002/star.19750270204

出版商:WILEY‐VCH Verlag GmbH    

年代:1975

数据来源: WILEY

摘要:

AbstractRadiolysis of Starch. A Contribution to Quantitative Determination of Several Radiolysis Products in Potato Starch and Wheat Flour. The amounts of formed desoxy‐compounds, which produce malonic dialdehyde during HIO4‐oxydation, as well as that of ω‐hydroxymaltol have been determined in irradiated potato starch and irradiated wheat flour in dependence on irradiation doses. With pure potato starch, G‐values*) of 0.03–0.04 for water soluble desoxy‐compounds and such ones of 0.02 for insoluble desoxy‐compounds were obtained. G‐values of desoxy‐compounds in an ethyl acetate‐acetone‐water extract (4: 5: 1 v/v) of irradiated potato starch and irradiated wheat flour showed a ratio of about 3: 1. When aqueous potato starch sols are irradiated desoxygroups in the high‐molecular starch molecule will also be found (inN2Oatmosphere: G‐values around 0.3).With ω‐hydroxymaltol it became apparent that the main part of this compound is formed after irradiation during storage. With pure potato starch G‐values around 0.015–0.02 were determined after 10 days of storage. When this material is heated after irradiation an increase of the hydroxymaltol content (G‐values: 0.025) is to be found.In the non‐irradiated materials traces of desoxy‐compound

ISSN:0038-9056    

DOI:10.1002/star.19750270205

出版商:WILEY‐VCH Verlag GmbH    

年代:1975

数据来源: WILEY

摘要:

AbstractConformational analogies between sugars, deoxy sugars, substituted sugars, glycosides and cyclitols are examined in relation to current hydrogen bond theories of sweetness. Although the sensory properties of saporous molecules are probably multifunctional in origin, hydrophilic and lipophilic substituents vary in their effects. The former depend on configuration, whereas the latter may either enhance sweetness by strengthening binding to the taste bud protein, or cause re‐alignment of the molecule, eliciting a bitter respons

ISSN:0038-9056    

DOI:10.1002/star.19750270206

出版商:WILEY‐VCH Verlag GmbH    

年代:1975

数据来源: WILEY

摘要:

AbstractInternational Standardization of Terms and Definitions Associated with Starch. Part 5. As a result of the fifth meeting of the “Terminology” group (SC 1/GT 1) of Technical Committee 93 (TC 93) of the International Standardization Organization (ISO) held in Berlin on February 19 and 20, 1974, a list was compiled giving definitions in English and French for another 40 terms. The French version (a), the English version (b) and an unofficial German version (c), supplemented by alphabetic indices, are presented for discussion.A total of 127 terms and definitions of the international vocabulary, approved by 20 countries, have up to now been published in International Standard 1227 of February 15, 1973 and its first supplement of March 15, 1

ISSN:0038-9056    

DOI:10.1002/star.19750270207

出版商:WILEY‐VCH Verlag GmbH    

年代:1975

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19750270208

出版商:WILEY‐VCH Verlag GmbH    

年代:1975

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19750270209

出版商:WILEY‐VCH Verlag GmbH    

年代:1975

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19750270210

出版商:WILEY‐VCH Verlag GmbH    

年代:1975

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19750270213

出版商:WILEY‐VCH Verlag GmbH    

年代:1975

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19750270216

出版商:WILEY‐VCH Verlag GmbH    

年代:1975

数据来源: WILEY